Incidence and prevalence of Down's syndrome--a discussion and report

This paper seeks to demonstrate that a slow but steady rise in the Down's syndrome population can be expected. Studies concerned with Down's populations have been critically examined along with factors effecting such populations; i.e. better health care, changes in maternal child-bearing age, under-diagnosis and prenatal diagnosis. It is suggested that better health care and a reduction in under-diagnosis could create a recognized increase in the Down's syndrome population, but that the effect of changes in child-bearing age is questionable. The effect of prenatal diagnosis is less than might be anticipated and changes in public attitudes could reduce this effect even further. In view of conflicting data from many of the studies examined, a small investigation was carried out in the Sheffield and Buckinghamshire areas. Results from these surveys indicate a current overall incidence rate of 4.63 per 10 000 though there are differences between the two areas.